This invention relates to controllers providing an electrical output signal in response to input signals.
Controllers are widely used for many purposes, for example in automatic process controls for manufacturing or chemical operations. Such controllers are usually employed in conjunction with transducers which sense the magnitudes of parameters relating to the operation to be controlled and which provide electrical signals fed to the controller. The controller processes these signals and provides electrical output signals for control purposes. The present invention is concerned with a controller having a number of information inputs and providing outputs for effecting a number of control operations. In the controller of the present invention, processing is effected digitally on a time-shared basis. Apart from the time-shared operation of the digital processing equipment, the control operations may be independent in the sense that input information from one source may be processed and used to provide an output signal independently of any other input information. It is thus convenient to refer to "control channels", a channel being concerned with taking input information for feeding to the processor and providing a corresponding processed output signal. Reference may be made to U.S. Pat. No. 3,374,464 and 3,267,434 as examples of prior multi-channel control system using digital data processing.
In prior types of multi-channel control systems using digital data processing, the programming of the data processing part of the equipment has been a complex job requiring special training and experience. It is a principal object of the present invention to provide an improved form of multi-channel controller in which the setting up of the algorithms for processing the information for the various channels is simply and readily done and in which the selected algorithms are visually displayed.
Although on one channel incoming information may be processed to provide an output, inter-connection of channels may be required for various purposes, e.g. input information may be used in more than one channel or output information from one channel may be used as an input in another channel. As explained later such interconnection may be provided and visually displayed in the controller of the present invention. It is convenient however in the first place to consider the equipment as having a number of control channels which can be operated independently on a time-shared basis utilising commondata processing equipment.